Boris Johnson wants a multibillion pound Channel bridge to be “entirely privately financed” after claiming the Channel Tunnel will be “full” by 2025.

The Foreign Secretary said it was a “curiosity” that the UK and France as two of the “most powerful economies in the world”, separated by approximately 21 miles of water, were connected by “only one railway line”.

He said French president Emmanuel Macron was supportive of the “committee of wise people” established to look at reviving the “great tradition” of UK-France collaboration in matters including defence, space and “infrastructure projects such as the idea of a new connection between our two countries”.

Mr Johnson’s defence of a bridge between the UK and France also saw him tell MPs that he expected there would be a “great swollen, throbbing, umbilicus of trade” between the UK and EU, with each side “mutually nourishing the other”.

Foreign Secretary Boris Johnson speaks in the Commons
Foreign Secretary Boris Johnson speaks in the Commons (PA)

Speaking in the Commons, shadow Foreign Office minister Khalid Mahmood said: “It’s estimated that we could build the Foreign Secretary’s Channel bridge at a cost of £120 billion.

“He wants to build bridges at the same time he is pushing for a hard Brexit which will push us away from the European Union.

“Or instead does he think that money could be well spent for the next six and a half years to give the National Health Service £350 million per week?”

Mr Johnson replied: “When the first Channel Tunnel was commissioned it was the vision of the then prime minister Margaret Thatcher that it should be entirely privately financed and there is no reason why we should not have the same ambition this time.”

On the “Brexit dividend”, Mr Johnson went on: “As the Prime Minister herself has said, there will unquestionably be substantial sums of money available to spend in this country on the priorities of the British people – including the NHS.”

SNP MP Patrick Grady (Glasgow North) earlier raised warnings that Channel ports faced “gridlock” if a Brexit transition arrangement was not “urgently” put in place.

He added: “What is the point of a 20-mile bridge if there’s going to be a 20-mile queue waiting to get on to it?”

Mr Johnson replied: “I think most people will appreciate that the existing Channel Tunnel is likely at the present rate to be full within the next seven years.

“That’s a very short time in the lifetime of a great infrastructure project.

“It is a curiosity that two of the most powerful economies in the world, separated by barely 21 miles of water, are connected by only one railway line, and I think it’s a matter for legitimate reflection by our two countries on the way forward.”

Tory MP Richard Graham (Gloucester) widened the issue to insist it appeared as if there would be a “unique and specific agreement” over Brexit, which would benefit both sides of the Channel.

He asked Mr Johnson if he agreed this should be the outcome of the talks soon to start, with Speaker John Bercow intervening to remind him the question was on a fixed link rather than Brexit.

Mr Johnson replied: “I think (Mr Graham) has hit on the notion of a metaphorical fixed link – a great swollen, throbbing, umbilicus of trade between us – I won’t say which way it’s going – each side mutually nourishing the other.

“I very much approve of the note of optimism that he strikes.”